1919 



Hall-Goodspced : Chrysil 



237 



Fig. '). A large ])laiit of Cltrii.sotluunnu.s 

 iiauKeosax var. rtriduhis. 1 indicates the as- 

 sumed soil-line; 2 the upper limits of the 

 iriain trunk; o the approximate up[>er limits 

 of the three- to four-vear-oM wood. 



in certain species of Hap- 

 lopappus rubber is con- 

 fined to the root or occurs 

 in approximately equal 

 amounts in root and stem. 

 As far as stem struc- 

 tures are concerned it is 

 more difficult to indicate a 

 sharp line of demarcation 

 between those which are 

 significant and those which 

 are not significant as far 

 as rubber content is con- 

 cerned. Figure 5 shows a 

 large plant of vlridiilus 

 (no. 565) and serves to 

 indicate the characteristic 

 method of branching and 

 the general configuration 

 of plants of this and other 

 varieties which we have ex- 

 amined. 



The assumed soil line, 

 the upper limits of the 

 main trunk, and the ap- 

 proximate upper limits of 

 the three- to four-year-old 

 wood are shown. The re- 

 sults listed in tables 7 and 

 8 suggest that only such 

 parts of the plant as lie 

 between 1 and 3 contain 

 sufficient rubber to war- 

 rant their harvesting if 

 the plants were used as a 

 commercial source of rub- 

 ber. 



In the various tables 

 above and in those which 

 follow, analyses of portions 



